Mercaptans for boosting the dyeing of human hair with direct dyes

ABSTRACT

A PROCESS IS DISCLOSED FOR IMPROVING THE COLORING OF HUMAN HAIR, ESPECIALLY LIVING HUMAN HAIR, WITH DIRECT DYES BY THE USE OF MERCAPTANS WHICH ARE INSOLUBLE OR DIFFICULTLY SOLUBLE IN WATER. THE MERCAPTANS ARE MERCAPTOCARBOXYLIC ACID ESTERS AND AMIDES. EMULSIONS OR DISPERSIONS OF THE MERCAPTANS CAN BE USED TO TREAT THE HAIR PRIOR TO DYEING OR THEY CAN BE COMBINED WITH THE DYEING COMPOSITION.

United States Patent Office 3,567,355 Patented Mar. 2, 1971 Int. Cl.A61k 7/12 US. Cl. 810.1 24 Claims ABSTRACT OF THE DISCLOSURE A processis disclosed for improving the coloring of human hair, especially livinghuman hair, with direct dyes by the use of mercaptans which areinsoluble or difficultly soluble in water. The mercaptans aremercaptocarboxylic acid esters and amides. Emulsions or dispersions ofthe mercaptans can be used to treat the hair prior to dyeing or they canbe combined with the dyeing composition.

The invention relates to substances which boost the activity of dyeingagents for human hair, and more particularly to so-called direct dyes,applied to living human hair.

It has previously been proposed to improve the action of direct dyes onhuman hair, by treating the hair, prior to dyeing, with readilywater-soluble mercapto compounds, such as thioglycolic acid or itsalkali or ammonia salts. However, in practice the production of uniformand reproducible coloring had met with diflieulties becausediscoloration of the hair occurs. It therefore has also been suggestedto carry out an ensuing treatment with oxidizing agents, such ashydrogen peroxide. However, this is an involved procedure and eliminatesthe advantages of the use of direct dyes which, by themselves, do notrequire the addition of oxidizers. Another considerable drawback uponthe use of the known water-soluble mercapto compounds, e.g.,thioglycolic acid or its alkali or ammonium salts, consists in the lackof storability of mixtures thereof with direct dyes.

The object of the invention is to present a process and agents for itsaccomplishment which facilitate coloring of human hair with direct dyeswhile avoiding the abovenamed disadvantages. This can be attained bytreating the hair with aqueous dispersions or emulsions of mercaptanswhich are insoluble or difficultly soluble in water.

Mercaptans of this kind which lend themselves to the purpose areparticularly mercaptocarboxylic acid esters, preferably alphaandbeta-mercaptocarboxylic acids, and/ or mercaptocarboxylic acid amides.

To be considered therefore are such compounds as thioglycolic acidesters, thiolactic acid esters and beta-mercaptopropionic acid esters ofprimary, secondary and tertiary monoand bivalent alcohols, such asmethyl-, dodecyl-, citronellyl-, tertiary heptyl alcohol, ethyleneglycol monoethyl ether, diethylene glycol, cyclohexanol and phenol;furthermore, thioglycolic acid diethanolamide, thioglycolic acid bis(beta-hydroxyethoxyethyl)-amide and thioglycolic acid formamide.

In many instances the esters of thioglycolic acids, of thiolactic acidand of mercaptopropionic acid with alcohols such as ethyl-, propyl-,butyl-, isobutyl-, hexyl-, isoheptyl-, isooctyl-, octyland tetrafurfurylalcohol and with diethyleneglycol monoethyl ether have proved especiallyapplicable.

Of the mercaptocarboxylic acid amides, thioglycolic acid cyclohexylamideand N,-N-bis-(mercaptoacetyl)-1,6-hexamethylenediamine are especially tobe mentioned.

The process can be carried out in such a manner that the hair first istreated with an emulsion or dispersion of the insoluble or difiicultlysoluble substituted mercaptans named, followed by rinsing of the hairand dyeing with the direct dyes in the conventional manner.

Direct dyes suitable for the purpose are nonionic compounds based uponanthraquinone or aminoanthraquinone or azo dyes. Particularly, thosedyestuffs named in British Pat. 957,119 can be employed or those soldunder the name Celliton (registered trademark).

Anionic direct dyes also are applicable, especially those based on acidazo dyes and triarylmethane dyes and also corresponding anthraquinoneand aminoanthraquin'one dyes.

Finally, cationic dyestuffs which dye directly also can be employed.

The dyes are employed in the conventional quantities of 0.1 to 5 weightpercent, preferably 0.5 to 3 percent. However, when the effect ofincreased color intensity is not desired, the booster agents accordingto the invention facilitate a substantial decrease in the amount ofdyestuif required, in some cases down to the amount otherwise used.

The booster liquids in the form of emulsions or dispersions containingthe water-insoluble or difficultly soluble substituted mercaptans alsocan be applied as the last rinse after shampooing of the hair to bedyed. The concentration of the active ingredients in all instances isapproximately 0.1 to 10 weight percent, and preferably 1 to 5 percent.

If desired, the booster treatment can also be combined with the dyeingprocess. The booster agents, in this case, are incorporated in thedyeing compounds either upon their manufacture or shortly beforeapplication. It goes without saying that chemical compatibilities of thebooster with the other materials present must be considered. It isfeasible not to use just one of the water-insoluble or difiicultlysoluble substituted mercaptans, but a mixture of several such compounds.

The pH value of the dispersions or emulsions containing these boosterscan be adapted to the prevailing conditions. Equally good results areobtained when the pretreatment liquid or the last rinse after shampooingis not alkaline, but neutral or acid.

The agents can be mixed with any desired wetting agents, detergents andWashing agents, especially those which are anionic or nonionic. Suitablewetting agents, detergents and washing agents are especiallyalkylbenzene sulfonates, fatty alcohol sulfates, alkylsulfonates, fattyacid ethanolamides, addition products of ethylene oxide on fatty acidsand fatty alcohols.

Furthermore, thickeners, e.g., methylcellulose, starch, higher fattyalcohols, Vaseline, paraffin oil and fatty acids can be admixed, alsoperfumes, i.e., essential oils, or hair grooming agents such aspantothenic acid and cholesterol.

These admixtures are employed in the quantities customary for thepurpose. Wetting agents and detergents particularly are employed at 0.5to 30 weight percent, thickeners in amounts of 0.1 to 25 weight percent,calculated on the total composition. The concentration of the directdyes depending upon the purpose amounts to up to 5 weight percent,preferably however to 0.1 to 2 weight percent, also calculated on thetotal composition.

The advantage of the novel process according to the invention reside inthe feasibility of considerably reducing the amount of dye to be usedwithout materially detracting from the color intensity; or, when usingthe customary amounts of dyestuif, to increase the intensityconsiderably. Other advantages are that not only the action of the dyeon the human hair is improved, but that resistance to abrasion andrubbing ensues. The singular effects named to a certain extent dependupon the boosting agent used and especially on the kind of dyestuifemployed. W 1

Finally, a particularly great advantage is found in the fact thatmixtures of direct dyes with 'the water-insoluble or difficultly solublesubstituted mercaptans named are storable for great lengths of time.These mixtures adv'alntageously are used in practice in the form ofcreams or pastes; Hair dyes containing water-soluble merca pto compoundscannot be stored for any length of time (see, e.g., Example 7 below).The invention now will be further expiained by the following examples.However, it should be understood that these are given merely by way ofillustration and not of limitation, and that numerous changes may bemade in the. details without departing from the spirit and the scope ofthe invention as hereinatferclaimedj 1 EXAMPLE 1 A strand of naturallygreyed human hair was saturated with a 1 weight percent aqueous solutionof a dyestuif having Formula 1 O 7 NH, I 1

t The solution had been adjusted to a pH of 9.5 with aqueous ammonia andwas allowed to act on the hair for 20 minutes at room temperature. Thiswas followed by shampooing and rinsing. The 'hair thus treated 'had alight red color. Y a

When the dyeing solution was fortified with 1 weight percentthioglycolic acid isobutylester, dispersed therein, a briliiant deep redcolor was attained.

EXAMPLE 2 A dyeing cream was prepared from 8 weight parts cetylstearylalcohol, 2 weight parts fatty alcohol C C 9 weight parts fatty alcohol.sulfate C C by heating these components to 80 C., adding 0.2 weightpart 2,2}- diaminoazobenzene, 0.4 weight part 4,4'-diaminoazobenzene,0.4 weight part l,4diamino-5-(1',4,7-trioxanonyl) anthraquinone, and 2weight parts thioglycolic aeid isopropylester, and emulsified at thistemperature with 70 parts water of like temperature. After cooling to 40C., the pH was adjusted to 9.5, and the emulsion made up to 100 partswith water. The dyeing cream thus obtained colored'living human greyhair to a beautiful dark brown.

Withthe same dyeing process, but without theaddition of the thioglycolicacid isopropylester, a brown color also was obtained which, however, hada much weaker hue.

EXAMPLE 3 Aqueous solutions or dispersions, respectively, were producedcontaining as dyestufi 1,4-diamino-2-chloro-3- (l',4',7'trioxanonyl-anthraquinone and. as a booster 5 weight percent of oneof the compounds listed in Table 1. The pH of these dispersions ,wasadjusted to 9.5 with ammonia. Grey hair was treated with these coloringbaths for-20 minutes at room temperature, rinsed with wate andshampooed.

In all instances the color obtained" was a distinct improvementpver thelight red color which was produced in the like process *but without theboosters named.

Corresponding results were obtained when, in lieu of the dyestuif named,a dye was used as listed in Table 2.

4 7 EXAMPLE 4 0 l rH t (2) which had been adjusted to a pH of 9.5 withammonia. The dye was allowed to act for 20 minutes at room temperature,and the hair was then'shampooed. A light red color was obtained. H i

An intensively brilliant red' color ensued when, at otherwise likeworking conditions, the hair was treated, prior to dyeing, with anaqueous-ammoniacal emulsion of 5 weight percent thioglycolic acidtertiary-butyl ester of zi pH of 9.5 for 20 minutes at room temperature.

Similar results were obtained when the pretreatment with thethioglycolic acid tertiary-butyl ester emulsion was carried out whenthis emulsion had a pH of 2 or of 7.

EXAMPLE 5 i Aqueous dispersions were produced containing as a cationicdyestulf 0.3 weight percent crystal violet and as booster one of thecompounds named in Table 3 in the amounts named therein. The dispersionswere adjusted to a pH'of 9.5 with ammonia. Living grey human hair wastreated with these dispersions for 20 minutes at room II I .temperature. After completed dyeing the hair was shampooed and dried.

having a pH of 9.5. After dyeing, the hair was shampooed,

.rinsed and dried. It had a brilliant red color. Changes in the time ofaction of the pretreatment to between 10 seconds and 30 minutes effectedcorresponding differences in the shading of the coloring obtained.

Without the .boosting: action of the thioglycolic acidtetrahydrofurfuryl ester, the red coloring was considerably weaker inall instances.

A brilliant red color also was obtained whenthe pretreatment batlr had apH of 2 or of 7.

EXAMPLE 7 Naturally grey living human hair was treated for 20 minutes atroom temperature with a solution containing 1 weight percent of adyestuif having Eormula 4 e e 1 in s Oz--CH3 EXAMPLE 8 Grey hair wastreated with an aqueous solution containing 1 weight percent of a dyehaving Formula 3 (see also Example 6) adjusted to a pH of 2.5, for 20'minutes at room temperature. The hair assumed a weak red color.

A strong red color was obtained when, at other-wise like treatment, thedyeing solution contained 5 weight percent thioglycolic acid hexylester.

TABLE 1 No. Material 1- Thioglycolic acid methyl ester. 2 Thioglycolicacid ethyl ester. 3- Thioglycolic acid propyl ester. 4 Thioglycolic acidbutyl ester.

5 Thioglycolic acid hcxyl ester.-

6- Thioglycolic acid octyl ester.

7 Thioglycolic acid dodecyl ester.

. Thioglycolic acid tetrahydrofuriuryl ester.

Thioglycolic acid citronellyl ester.

. Thioglycolic acid isopropyl ester.

Thioglycolic acid isobutyl ester.

12 Thioglycolic acid isoheptyl ester.

13 Thioglycolic acid isooctyl ester.

14. Thioglycolic acid tertiary-butyl ester.

15 Thioglycolic acid tertiary-heptyl ester.

16. 'Ihioglycolic acid ethylene glycol monoethyl ether ester. 17..--Thioglycolic acid diethylene glycol ester.

18. Thioglycolic acid diethylene glycol monoethyl ether ester. 19...-Thioglycolic acid phenyl ester.

Thiolactic acid ethyl ester.

Beta-mercaptopropionic acid butyl ester.

2 Thioglycolicacid cyclohexamide.

23. N,N'-bis-(mercaptoacetyl) -1,6-hexamethylenediamine.

TABLE 2 Name of dye Color Index No. Supracene Red G 17045 Supracene RedB 17070 Supracene Violet 4 BF 620 Supracene Blue GE Acid Blue 66 IsolaneGrey BRLS Acid Black 140 TABLE 3 Weight No. Material percent 1Thioglycolic acid diethanolamide 3 2 Thioglyoolic acidhydro'xyethoxyethylamide 1 3 Thioglycolicacid-di-(hydroxyethoxyethyl)amide- 2 TABLE 4 Weight No. Material percent1 Thioglycolic acid ethyl ester 3 2 Thioglycolic acid hexyl ester 3 3'Ihioglyeolic acid tetrahydroiurfuryl ester 3 g Thioglycolic acidisopropyl ester g 3 3 i Thioglycolic acid diethanolaznide 5N,N-bis-(mercaptoacetyl)-1,6-hexamethylenediamine 5 6 EXAMPLE 9'Coloring baths :were produced containing 1 weight percent of an anionicdyestulf having Formula 3 (see Examand further containing as booster oneof the compounds listed in Table 4 in the quantities named therein. Thedyeing liquid was adjusted to a pH of 9.5 with aqueous ammonia.

Living human hair was dyed by treating it with these liquids for 20minutes at room temperature. After dyeing, the hair was shampooed anddried. In all instances, the coloration was a considerable improvementover the weak red color obtained under the same conditions but withoutthe presence of the booster in the dyeing liquid.

What is claimed is:

1. A process for boosting the action of a directdye on human hair whichcomprises treating said hair substantially at room temperature with adispersion of substantially 0.1 to 10 weight percent of compoundsselected from the group consisting of water-insoluble or difiicultlysoluble esters of thioglycolic acid, thiolactic acid, betamercaptopropionic acid with primary, secondary and tertiary mono anddivalent alcohols; thioglycolic acid diethanolamide, thioglycolic acidmono and dihydroxyethyl amide, thioglycolic acid formamide, thioglycolicacid cyclohexamide, N,N -bis- (mercaptoacetyl) -1,6-hexarnethylenediamine, and mixtures thereof and thereafter applying said dye.

2. A process according to claim '1 wherein said alcohols are citronellylalcohol, mono and diethylene glycol monoethyl ether, diethylene glycol,cyclohexanol, phenol, tetrafurfuryl alcohol, or mixtures thereof.

3. A process according to claim 1, in which said com pound isthioglycolic acid ethyl ester.

4. A process according to claim 1, in which said compound isthioglycolic acid butyl ester.

5. A process according to claim 1, in which said compound isthioglycolic acid dodecyl ester.

6. A process according to claim. 1, in which said compound isthioglycolic acid isopropyl ester.

7. A process according to claim 1, in which said compound isthioglycolic acid isobutyl ester.

8. A process according to claim 1, in which said compound isthioglycolic acid isooctyl ester.

9. A process according to claim 1, in which said compound isthioglycolic acid tertiary-butyl ester.

10. A process according to claim 1, in which said compound isthioglycolic acid tertiary-heptyl ester.

11. A process according to claim 1, in which said compound is thiolacticacid ethyl ester.

:12. -A process according to claim 1, in which said compound isbeta-mercaptopropionic acid butyl ester.

13. A process for boosting the action of a direct dye on human hairwhich comprises treating said hair substantially at room temperaturewith the application of said dye in a dispersion of substantially 0.1 to10 weight percent of compounds selected from the group consisting ofwater-insoluble or diflicultly soluble esters of thioglycolic acid,thiolactic acid, beta mercaptopropionic acid with primary, secondary andtertiary mono and divalent alcohols; thioglycolic acid diethanolamide,thioglycolic acid mono and dihydroxyethoxyethyl amide, thioglycolic acidformamide, thioglycolic acid cyclohexamide, N,Nbis-(mercaptoacetyl)-16-hexamethylene diamine, and mixtures thereof.

14. A process according to claim 13 wherein said alcohols arecitronellyl alcohol mono and diethylene glycol monoethyl ether,diethylene glycol, cyclohexanol, phenol, 24. A process according toclaim 13, in which said tetrafurfuryl alcohol or mixtures thereof.compound is beta-mercaptopropionic acid butyl ester.

15. A process according to claim 13 in which said compound isthioglycolic acid ethyl ester. References Cited 16. A process accordingto claim 13, in which said 5 UNITED STATES PATENTS compound isthiogly-colic acid butyl ester.

17. A process according to claim 13, in which said g::

compound is thioglycolic acid dodecyl ester.

18. A process according to claim 13, in which said compound isthioglycolic acid isopropyl ester. 10 a 19. A process according to claim13, in which said FOREIGN PAFSEITITS compound is thioglycolic acidisobutyl ester. 833,809- 4/1960 Great i f 16788 20. A process accordingto claim 13, in which said 906,526 9/1962 Great Bntam 167*88 compound isthioglycolic acid isooctyl ester.

21. A process according to claim 13, in which said 2,615,828 10/1952Haefele .....16787.1

15 ALBERT T. MYERS, Primary Examiner compound is thioglycolic acidtertiary-butyl ester. V. C. CLARKE, Assistant Examiner 22. A processaccording to claim .13, in which said compound is thioglycolic acidtertiary-heptyl ester. XR

23. A process according to claim 13, in which said 92 71 72 compound isthiolactic acid ethyl ester. 20

